The following documents are known as the background art of the present invention:
Patent document No. 1: Japanese Unexamined Patent Publication No. S52-121538
Patent document No. 2: Japanese Unexamined Patent Publication No. 2000-198148
Recently, a tire (known as a jointless tire) has been proposed, having a structure wherein no joints are formed in the circumferential direction, using single fibrous cords as reinforcement material for the reinforced layer of the tire.
A conventional method for producing the above-mentioned single cord has been known, wherein a fibrous cord wound on a bobbin is withdrawn therefrom, treated with an adhesive agent and then heat-set. However, this method is problematic in that operating and energy efficiency are low.
On the other hand, another method has been known, wherein a plurality of single cords are arranged parallel to each other, simultaneously treated with an adhesive agent and then heat-set. However, in this method, since a large number of cords arranged parallel to each other are used, there is a tendency for the cords to become entangled or broken in the process of applying adhesive. When the breakage of cords occurs, the broken cords entangle with the other cords, and the removal of the broken cords or the rearrangement of the remaining cords may be required. This results in a loss of cords, times and labors.
In Patent document No. 1, a method of producing a tire cord is disclosed wherein a plurality of warps consisting of yarns for single tire cords are woven with wefts at predetermined intervals in the longitudinal direction of the warps in order to provide a long mesh cord fabric (or tire fabric), the cord fabric is unwound and then the fabric is divided into a plurality of large individual sections having a width of 2 to 30 cm by expanding the fabric in the weft direction to increase intervals between the large individual sections and cutting the weft yarns between the large individual sections, each of the resultant plurality of large individual sections is divided into a plurality of small individual sections having a width of 0.5 to 5 cm by increasing the intervals between the small individual sections in the weft direction of the fabric and cutting the weft yarns between the small individual sections, and each of the warp yarns (single yarns) are collected from the each of the divided small individual sections, and wound.
In Patent document No. 2, a method of producing a tire cord from cord fabric is disclosed, wherein a long woven cord fabric in produced by weaving a number of single yarns for a tire cord with weft yarns woven into the warp yarns at intervals in the longitudinal direction thereof, and then subjected to adhesive treatment and heat set (weft yarns preliminarily treated with Teflon (trade mark) may be used for preventing the weft yarns from adhering to the warp yarns). In this method, when unwinding the wound cord fabric in one direction, the warp yarn becomes separated one by one from a edge of the fabric. At this time, positions at which the warp yarns are withdrawn from the fabric are arranged so that the distance between the withdrawing portion of the warp yarn and the unwinding portion of the cord fabric increases in the arrangement order of the warp yarns from the edge to the inner side. If all the warp yarns could not be withdrawn from the cord fabric in one procedure, the above-mentioned operations must be repeated, and in such a case, part of the weft yarns in the fabric from which the warp yarns have been withdrawn must be cut and removed.
In the above-mentioned prior art methods, means are necessary for withdrawing the warp yarns from the cord fabric (a rough-meshed fabric) containing fibrous cord yarns as the warp yarns, and for cutting and removing weft yarns. Accordingly, production is complicated and expensive, and the production process becomes complicated and difficult, resulting in increased production costs.
Regarding the reinforcement cords for rubber or resin, it has been required that the reinforcement cords have a high adhesive strength to a rubber or resin material. In the above-mentioned method, it is desirable that the warp yarns and the weft yarns do not adhere to each other so that the warp yarns are easily separable from the weft yarns. However, in order to satisfy such a requirement, the adhesive strength of the resultant fibrous cord to a rubber or resin material may be insufficient.